The Weekend Wonk: Jennifer Francis on Arctic Sea Ice

September 22, 2012

Dr. Jennifer Francis of Rutger’s Institute of Marine and Coastal Sciences is featured in my sea ice wrap video, which should be out early in the week.

Here is a lecture she gave in January of 2012. Longish, but worth dipping into, as she summarizes some of the most recent research in regard to the effects of shrinking arctic ice on weather and climate in the temperate latitudes – the so-called “arctic paradox” so beloved by Fox News – “if there’s global warming, why are we having this record snow storm?”.

What she told me in a recent interview was that the sea ice record is not something that we just pay attention to in September – there will, in fact, be reverberations that will make fall and winter “very interesting” around the globe.

As temperatures over the Arctic Ocean fall with the approach of winter, the extra energy that was absorbed during summer must be released back into the atmosphere before the water can cool to freezing temperatures. Essentially, this loads the atmosphere with a new source of energy—one that affects weather patterns, both locally and on a larger scale. In spring, a similar phenomenon also occurs, but it involves snow cover on northern land areas. Snow has been melting progressively earlier each year; this past June and July it disappeared earlier than ever before. The underlying soil is then exposed to strong spring sun, which allows it to dry and warm earlier – contributing to Arctic amplification in summer months.

The difference in temperature between the Arctic and areas to the south is what drives the jet stream, a fast-moving river of air that encircles the northern hemisphere. As the Arctic warms faster, this temperature difference weakens, as does the west-to-east wind of the jet stream. Just as a river of water tends to meander when it reaches the gentle slopes of coastal plains, a weaker jet stream tends to have steeper north-south waves. Arctic amplification also stretches the northern tips of the waves farther northward, which favors further meandering. Meteorologists know that steeper waves are slower to shift westward.

The weather we experience at mid-latitudes is largely dictated by these waves in the jet stream. The slower the waves move, the longer the weather associated with them will persist. Essentially, “hot,” “dry,” “cold,” and “rainy” are all terms to describe very normal weather conditions. It’s only when those conditions persist in one area for too long that they are dubbed with the names of their extreme alter egos: heat waves, drought, cold spells, and floods. And these kinds of extreme events are precisely what we’ve seen more of in recent years.

Global warming now has a face and a fingerprint that directly touch each of our lives. Rather than just a gradual increase in temperature, we can recognize its influence in a shift toward more extreme weather events. A warmer atmosphere also means a moister atmosphere, so any given storm will have more moisture and energy to work with, increasing the chances of flooding or heavy snows. Arctic amplification adds another mechanism to the mix, making extreme weather more likely. The loss of ice and snow in the far north may load the dice for “stuck” weather patterns, compounding potential risks for our economy, our health, and our security.

It’s easier to see that there’s a slight downward trend if you compare ice extent with a straight line (1979-2009 average), so here’s the same graph but with the addition of the deviation from the average shown at the bottom, in red:

The only decent sea-ice extent measurements we have are from satellite imaging. The Nimbus satellites first collected visible and infrared spectrum photographs of sea ice in the mid-1960s, and collected better sea ice data from passive microwave radiometers starting with Nimubs-5, which launched in December, 1972.

The first few years of the satellite record showed an increasing ice extent trend, but that early data is never included in the graphs produced these days by NOAA, the NSIDC, etc. Instead, the graphs we see start in 1979, with data from the improved multi-channel passive microwave radiometer aboard Nimbus 7.

Blogger Steven Goddard thinks that the reason that the data from the early and mid-1970s are not shown in the graphs (which instead start in 1979) is that Climate Movement alarmists want to disguise the fact that when the early and mid-1970s are included it is apparent that there’s been little actual long-term change in sea-ice extent. Of course, the “innocent” explanation is that the instruments weren’t as good before 1979. The truth is probably a little of each: the lower quality of the earlier instruments is both a reason and an excuse for ignoring the inconvenient early data.

The first four Nimbus satellites had only visible and IR optical instruments, which couldn’t see through clouds.

Seasat-1:
Launched 27 June 1978, and failed 10 October 1978. It carried a duplicate of the Nimbus-7 SMMR, but apparently most of its data has also been lost. (!!!)http://southport.jpl.nasa.gov/scienceapps/seasat.html
Note that its short data record presumably included SMMR measurements of the 1978 Arctic sea-ice minimum.

Comparisons between the earlier ESMR data and the later SMMR data would be more reliable if there’d been some overlap between them, and it’s a rotten shame the government has apparently lost so much of the old data. But the 4-1/2 years of Nimbus-5 data surely has some value, and I agree with Steve Goddard that it should not just be ignored.

Were there any other early satellites which were doing sea-ice measurements?

DAVE! Long time no see.
boy, did you photoshop that graph from Cryosphere today, or do they
make a version with just the top line?

Lord Monckton uses the same slight of hand, without the photoshopping,
just directing people’s attention to the top line and quickly moving on..
as I’ll demonstrate in an upcoming vid. Hmm, think I’ll include your post
as well as the tea party contribution.
I’ve taken the liberty of saving your graph here

and anyone that wants to see the original from the U of Illinois,
showing global sea ice in decline – can click here

seriously, if you need photoshop services, call me, I’m sure I can
beat whoever’s doing it for you.

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